From 9b7725ee181617b2e0ea13189837b0724ab964b8 Mon Sep 17 00:00:00 2001
From: John Wiegley <johnw@newartisans.com>
Date: Sat, 26 Jul 2008 23:55:06 -0400
Subject: Added a simple optimization to the way amount strings are parsed.

---
 amount.cc  | 14 ++++++++++----
 amount.h   |  5 +++--
 valexpr.cc | 32 ++++++++++++--------------------
 3 files changed, 25 insertions(+), 26 deletions(-)

diff --git a/amount.cc b/amount.cc
index 1ac2f407..3a10828c 100644
--- a/amount.cc
+++ b/amount.cc
@@ -1062,7 +1062,7 @@ void parse_annotations(std::istream& in, amount_t& price,
 	      << "  tag " << tag);
 }
 
-void amount_t::parse(std::istream& in, unsigned char flags)
+bool amount_t::parse(std::istream& in, unsigned char flags)
 {
   // The possible syntax for an amount is:
   //
@@ -1114,8 +1114,12 @@ void amount_t::parse(std::istream& in, unsigned char flags)
     }
   }
 
-  if (quant.empty())
-    throw new amount_error("No quantity specified for amount");
+  if (quant.empty()) {
+    if (flags & AMOUNT_PARSE_SOFT_FAIL)
+      return false;
+    else
+      throw new amount_error("No quantity specified for amount");
+  }
 
   _init();
 
@@ -1205,6 +1209,8 @@ void amount_t::parse(std::istream& in, unsigned char flags)
 
   if (! (flags & AMOUNT_PARSE_NO_REDUCE))
     reduce();
+
+  return true;
 }
 
 void amount_t::reduce()
@@ -1215,7 +1221,7 @@ void amount_t::reduce()
   }
 }
 
-void amount_t::parse(const std::string& str, unsigned char flags)
+bool amount_t::parse(const std::string& str, unsigned char flags)
 {
   std::istringstream stream(str);
   parse(stream, flags);
diff --git a/amount.h b/amount.h
index 3df04c1d..ef1d2a3d 100644
--- a/amount.h
+++ b/amount.h
@@ -263,9 +263,10 @@ class amount_t
 
 #define AMOUNT_PARSE_NO_MIGRATE 0x01
 #define AMOUNT_PARSE_NO_REDUCE  0x02
+#define AMOUNT_PARSE_SOFT_FAIL  0x04
 
-  void parse(std::istream& in, unsigned char flags = 0);
-  void parse(const std::string& str, unsigned char flags = 0);
+  bool parse(std::istream& in, unsigned char flags = 0);
+  bool parse(const std::string& str, unsigned char flags = 0);
   void reduce();
 
   amount_t reduced() const {
diff --git a/valexpr.cc b/valexpr.cc
index 5b5d29ba..4fed821e 100644
--- a/valexpr.cc
+++ b/valexpr.cc
@@ -772,29 +772,21 @@ value_expr_t * parse_value_term(std::istream& in, scope_t * scope,
       // When in relaxed parsing mode, we do want to migrate commodity
       // flags, so that any precision specified by the user updates
       // the current maximum precision displayed.
-      try {
-	pos = (long)in.tellg();
+      pos = (long)in.tellg();
 
-	unsigned char parse_flags = 0;
-	if (flags & PARSE_VALEXPR_NO_MIGRATE)
-	  parse_flags |= AMOUNT_PARSE_NO_MIGRATE;
-	if (flags & PARSE_VALEXPR_NO_REDUCE)
-	  parse_flags |= AMOUNT_PARSE_NO_REDUCE;
+      unsigned char parse_flags = 0;
+      if (flags & PARSE_VALEXPR_NO_MIGRATE)
+	parse_flags |= AMOUNT_PARSE_NO_MIGRATE;
+      if (flags & PARSE_VALEXPR_NO_REDUCE)
+	parse_flags |= AMOUNT_PARSE_NO_REDUCE;
 
-	temp.parse(in, parse_flags);
-      }
-      catch (amount_error * err) {
-	// If the amount had no commodity, it must be an unambiguous
-	// variable reference
-	if (std::strcmp(err->what(), "No quantity specified for amount") == 0) {
-	  in.clear();
-	  in.seekg(pos, std::ios::beg);
-	  c = prev_c;
-	  goto parse_ident;
-	} else {
-	  throw err;
-	}
+      if (! temp.parse(in, parse_flags | AMOUNT_PARSE_SOFT_FAIL)) {
+	in.clear();
+	in.seekg(pos, std::ios::beg);
+	c = prev_c;
+	goto parse_ident;
       }
+
       node.reset(new value_expr_t(value_expr_t::CONSTANT));
       node->value = new value_t(temp);
       goto parsed;
-- 
cgit v1.2.3